What is CVE-2026-8899?

CVE-2026-8899 is a medium-severity vulnerability in Gapgag55 Auto Thumbnails, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-05-27.

How severe is CVE-2026-8899?

Medium severity. CVSS v3 base score is 6.4 out of 10.

XSS in Gapgag55 Auto Thumbnails

CVE-2026-8899

The Auto Thumbnail plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'thumbnails' shortcode in all versions up to, and including, 1.0. This is due to insufficient input sanitization and output escaping on the shortc…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.000 (9.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.

Affected products

Gapgag55 Auto Thumbnails — versions 0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

security@wordfence.com
security@wordfence.com
security@wordfence.com

Frequently asked questions

What is CVE-2026-8899?: CVE-2026-8899 is a medium-severity vulnerability in Gapgag55 Auto Thumbnails, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-05-27.
How severe is CVE-2026-8899?: Medium severity. CVSS v3 base score is 6.4 out of 10.